| Annotated protein: | Calpain-1 catalytic subunit (EC 3.4.22.52) (Calcium-activated neutral proteinase 1) (CANP 1) (Calpain mu-type) (Calpain-1 large subunit) (Micromolar-calpain) (muCANP). Gene symbol: CAPN1. Taxonomy: Rattus norvegicus (Rat). Uniprot ID: P97571 |
| antibody wiki: | |
| SynGO gene info: | SynGO data @ CAPN1 |
| Ontology domain: | Biological Process |
| SynGO term: | protein catabolic process at postsynapse (GO:0140249) |
| Annotated paper: | Lu X, et al. "Calpain-mediated degradation of PSD-95 in developing and adult rat brain" Neurosci Lett. 2000 Jun 2;286(2):149-53 PMID:10825658 |
| Figure(s): | Figure 1, 3 |
| Annotation description: | Figure 1: Western blots of rat forebrain synaptic membranes indicated that the PSD-95 (DLG4) antibodies recognized a doublet band, at a molecular weight of about 95 kDa, under control conditions (Fig. 1). Purified calpain I (CAPN1, calpain 1, μ-calpain) treatment resulted in a decrease in native PSD-95 protein, and in the formation of two prominent truncation products, two doublet bands migrating at 50 and 36 kDa, respectively. This effect was completely blocked by calpain inhibitors, either calpain inhibitor III (100 μM) or leupeptin (100 μM). Figure 3; Effect of calcium treatment of frozen-thawed brain sections and NMDA treatment of organotypic hippocampal cultures on PSD-95. The proteolytic pattern was identical to that obtained with calpain I digestion of synaptic membranes, with clear identification of the 50 and 36 kDa bands. To further verify that calpains, but not other proteases, were responsible for the calcium-induced degradation of PSD-95, a series of protease inhibitors were added to the incubation buffer. Calcium-dependent degradation of PSD-95 was not affected by the serine protease inhibitor, aprotinin (50 μM), but was totally blocked by EGTA (2 mM) and two calpain inhibitors, calpain inhibitor III (100 μM) and leupeptin (100 μM). Thus, calcium-mediated PSD-95 degradation in frozen-thawed rat brain sections is due to calpain activation |
| Evidence tracking, Biological System: | Intact tissue Cultured neurons |
| Evidence tracking, Protein Targeting: | Antagonist / agonist Antibody (detection) |
| Evidence tracking, Experiment Assay: | Western blot |
| Annotator(s): | Frank Koopmans (ORCID:0000-0002-4973-5732) Guus Smit (ORCID:0000-0002-2286-1587) Matthijs Verhage (ORCID:0000-0002-2514-0216) |
| Lab: | Department of Functional Genomics, Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands |
| Additional literature: | In cultured hippocampal neurons, NMDA-R-dependent activation of calpain resulted in the N terminus cleavage of β-catenin. @ PMID:17270735 Western blots were performed with various antibodies to quantify the amounts of the various species of GluR1, GluR2, GluR3 and NR2B subunits. The results indicate that calpain activation decreased the amount of all the intact subunits in Triton-insoluble fractions @ PMID:10773202 Biochemical and immunocytochemical studies demonstrated that in cortical cultures, prolonged glutamate or NMDA treatment reduced the level of surface and total GluR1, but not GluR2, subunits in a calpain-dependent manner. @ PMID:17234699 |
| SynGO annotation ID: | 4739 |
| Dataset release (version): | 20231201 |
| View annotation as GO-CAM model: |  |